byrdman454

I have had my '88 S4 for about 10 months and 10,000 miles. I recently received the dreaded belt tension warning light. The PO had replaced the belt, water pump and tensioner roller so these components only have about 20,000 miles on them. The tension was spot on and after following some advice from Wally P, the tensioner leaks all the fluid when I attempt to refill.

Finally to the question:
Can I remove the tensioner and rebuild it without removing the large belt cover and the belt itself?

If I end up having to remove these anyway, should I go ahead and do a complete TB and WP change?

Thanks!

ErnestSw

How long ago was the TB/WP job done? It should be done every 5 years regardless of the miles.
IIRC the fill and drain nipples screw into the tensioner housing. I don't know whether the nipple itself is the valve. If it is, then that may be all you need to replace.
You have to remove the TB cover to remove the tensioner.
HTH

byrdman454

The TB/WP service was done in July of 2001. Since that date it has only had 20,000 miles put on the car.

ErnestSw

I wouldn't do the TB/WP if it were my car. Can you see where the oil is leaking from?

byrdman454

I have not determined where the leak is from. I believe it has to be from the tensioner boot or the gasket between itself and the engine. Either option requires me to remove the tensioner.

The tensioner rebuild was not on the Porsche service invoice I received from the PO. Don't understand why...

I can see the tensioner with the small TB cover (passenger side) removed. Can I remove the tensioner with only this cover off, or will I have to remove the larger cover as well?

byrdman454

I have not determined where the leak is from. I believe it has to be from the tensioner boot or the gasket between itself and the engine. Either option requires me to remove the tensioner.

The tensioner rebuild was not on the Porsche service invoice I received from the PO. Don't understand why...

I can see the tensioner with the small TB cover (passenger side) removed. Can I remove the tensioner with only this cover off, or will I have to remove the larger cover as well?

ErnestSw

Having looked in the manual to refresh my memory, I'm pretty sure you'll have to remove the center cover as well. You should get a tensioner rebuild kit from www.928sp or one of the other big three and replace the rollers as well.

byrdman454

The larger tensioner roller was replaced 20,000 miles ago when the PO had the TB/WP replaced. As for the idler roller, I was under the impression that it is optional and that my current mileage (@75,000) would not require the change. Am I wrong?

Thanks for the info about the large cover. I was afraid of that. Taking that cover off requires alot more work.

Niklas Kampe

It IS possible to remove and reinstall the tensioner without removing the center T-belt cover and the belt itself. I did it on my car. However, it is quite tricky. Removing is not so bad, but putting back is difficult (there are so many things you have to take care of simultaneously: make sure the gasket gets aligned properly, screw in the mounting bolts, get the dowel pin to align with the dimple in the tensioner arm - quite difficult with only two hands).

If I had to do the job again, I would probably rather remove the center cover first. It's more work, but it makes the job easier.

Best regards
Niklas Kampe
Finland, Europe
928 S4 1987

SteveCo

I'm with Ernest and Niklas on this one...you need to strip things down to do this one properly.

I came across a picture from the service manual and John Pirtle's site that was helpful to me in visuallizing the whole T-belt system before I did my car...page 15-14 of the WSM show a nice view of the timing belt and related equipment in place. You can see that the tensioner is way down on the lefthand side of the picture. Hard to believe you can get at it without the center belt cover removed...but it may be!

You might also me interested in the results of a recent thread on the tensioner, it's evolution and part numbers. Bill Ball did a very thorough run down on this topic...check out:
http://www.billsworkshop.com/tensioner/tensioner.htm

Regards,
SteveCo in St. John's

Chris Lockhart

It "CAN" be done, as my wife and I just did it three weeks ago!!!!!!! I had already put everything back in place, tensioned the belt, and then went to service the tensioner, and found that I had torn the tensioner boot during installation. Once I got a new boot (and mount gasket) I rotated the engine to the 45 degree mark as per the normal t-belt routine, then I took only the upper 2 or 3 bolts out of the center cover, as well as the large bolt that goes through the cover and the tensioner, then I pulled the center cover back and slid the passenger side of the cover over the pulleys to hold it out of the way, and then I removed the tensioner. Installation was actually easier than the normal method, as it was very easy to seat the plunger from the warning system back into the tensioner without having to wiggle it in past the tensioner while installing the plunger with the tensioner arm. Then I put the 3 bolts back into the tensioner and snugged them up, put some tension on the belt, and put the cover back. Then I went through the normal belt tension sequence and installed the upper covers, etc.... At the point I was at during re-assembly, there was no way I was gonna take EVERYTHING back apart, unless I proved to myself that it had to be done that way. Luckily all worked in my favor, and now I have put roughly 1K miles on the new belt. Almost time to retension. Good luck with it.

Garth S

Glad to read of Chris L's experience on tensioner removal from 'within the covers'.
For my $0.02, ~ 2 months ago, a catastrophic WP failure (failed bearing housing) had me inside a '88 doing some of the same.
If you cannot wrestle the tensioner out as Chris has done, then the center cover must go. In my case, this cover would not clear the harmonic damper-so 'locked down @ 45 deg', pull the crank bolt etc.
When you're this far into a tensioner service, another $40 will have a new TB installed ,should you have any doubts re. prior service @ 20K miles. Trust is part of the game- trust the WP , and consider replacing the TB if you get in this far ($0.02 opinion!).
With covers off (enough) to view the tensioner, hopefully the leak will be visible; as this is an unpressurized system, odds are, the rubber boot looks great but leaks like a sieve. This can easily be serviced in situ ( as can the O-ring), using end cutters to close the clamping ring,( or purchase the hose clamp type with a screw adjustor). -if the block gasket leaks,well, off it comes.
As far as tensioner/idler rollers go, delicately rotate them: If 'as smooth as silk', move on - if not, press in new bearings/replace as reqd.
Good luck

SteveCo

As Chris has pointed out, this is possible, then. But I'm with Garth concerning the level of effort for the end result. If the tensioner was not "rebuilt" when the t-belt was last replaced, then what's the confidence level on the other critical components like the idlers, rollers and even the waterpump? This is one area that you really do not want to leave to chance.

If the other components can be check in-situ, then a tensioner only R&R makes sense. If not, it might be worth the peace of mind to pull all the belt covers and verify the status of the components. Whether you opt for a t-belt swap at that point is a judgement call, but at least you will have the first hand knowledge of the condition of the complete t-belt system condition.

This is a tough one to call. At 20,000 miles into a new t-belt it is almost too early to swap it again, but too late to consider it "just done". I'm about 2,500 miles into my new t-belt...hope I don't have to make this type of decision for at least 5 years (or 50,000 miles)!

Regards,
SteveCo in St. John's